why start with this technology? >> you know, when i started thinking about the structure of the book, it occurred to me that actually part of what i do is look for the white ancestors and her family tree. as well, the story of so many generations of people who emerged from slavery. and i thought to myself, we actually know where the story ends. with michele obama, you know the first african-american first lady in the white house. but the question is, where did it begin? it is a little unorthodox. i didn't know really when i started doing and how well it would work. i thought that i would learn as to 700 and i also thought that because there was so much silence over the generations the peeling back of the layers in hearing what little bits and pieces people knew and what they did not know. but that would give you a sense of the reverberations that slavery had over time. but you would be kind of drawn to this. >> i think silence is one of the most consistent themes in the book. the pain of this task. discussing the wa